Fixed setting OpenGL mode multiple times on Windows

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%40374

docs.html

@@ -16,6 +16,7 @@ be found at the <A HREF="http://www.libsdl.org/"> main SDL page</A>.
 Major changes since SDL 1.0.0:
 </H2>
 <UL>
+	<LI> 1.2.5: Fixed setting OpenGL mode multiple times on Windows
 	<LI> 1.2.5: Added support for Qtopia on embedded systems (thanks David!)
 	<LI> 1.2.4: Added initial support for Atari (thanks Patrice!)
 	<LI> 1.2.4: Added support for building SDL for EPOC/SymbianOS 6.0

src/video/wincommon/SDL_wingl.c

@@ -36,11 +36,50 @@ static char rcsid =
 #define DEFAULT_GL_DRIVER_PATH "OPENGL32.DLL"
 #endif
 
+/* If setting the HDC fails, we may need to recreate the window (MSDN) */
+static int WIN_GL_ResetWindow(_THIS)
+{
+	int status = 0;
+	int can_reset = 1;
+
+	/* If we were passed a window, then we can't create a new one */
+	if ( SDL_windowid ) {
+		can_reset = 0;
+	}
+#ifndef _WIN32_WCE /* FIXME WinCE needs the UNICODE version of CreateWindow() */
+	if ( can_reset ) {
+		/* Save the existing window attributes */
+		LONG style;
+		RECT rect = { 0, 0, 0, 0 };
+		style = GetWindowLong(SDL_Window, GWL_STYLE);
+		GetWindowRect(SDL_Window, &rect);
+		DestroyWindow(SDL_Window);
+		SDL_Window = CreateWindow(SDL_Appname, SDL_Appname,
+		                          style,
+					  rect.left, rect.top,
+                                          (rect.right-rect.left)+1,
+                                          (rect.top-rect.bottom)+1,
+		                          NULL, NULL, SDL_Instance, NULL);
+		if ( SDL_Window ) {
+			this->SetCaption(this, this->wm_title, this->wm_icon);
+		} else {
+			SDL_SetError("Couldn't create window");
+			status = -1;
+		}
+	} else
+#endif /* !_WIN32_WCE */
+	{
+		SDL_SetError("Unable to reset window for OpenGL context");
+		status = -1;
+	}
+	return(status);
+}
 
 int WIN_GL_SetupWindow(_THIS)
 {
 	int retval;
 #ifdef HAVE_OPENGL
+	int i;
 	int pixel_format;
 
 	/* load the gl driver from a default path */
@@ -51,6 +90,7 @@ int WIN_GL_SetupWindow(_THIS)
 		}
 	}
 
+	for ( i=0; ; ++i ) {
 		/* Get the window device context for our OpenGL drawing */
 		GL_hdc = GetDC(SDL_Window);
 		if ( GL_hdc == NULL ) {
@@ -89,9 +129,19 @@ int WIN_GL_SetupWindow(_THIS)
 			return(-1);
 		}
 		if( !SetPixelFormat(GL_hdc, pixel_format, &GL_pfd) ) {
+			if ( i == 0 ) {
+				/* First time through, try resetting the window */
+				if ( WIN_GL_ResetWindow(this) < 0 ) {
+					return(-1);
+				}
+				continue;
+			}
 			SDL_SetError("Unable to set HDC pixel format");
 			return(-1);
 		}
+		/* We either succeeded or failed by this point */
+		break;
+	}
 	DescribePixelFormat(GL_hdc, pixel_format, sizeof(GL_pfd), &GL_pfd);
 
 	GL_hrc = this->gl_data->wglCreateContext(GL_hdc);